A wide variety of memory devices are found in electronic systems. For example, dynamic random access memory devices (“DRAM”) are commonly used as system memory in computer systems. Although DRAM devices are highly reliable, they nevertheless do, at times, malfunction. Common DRAM device malfunction mode are data retention errors, which result when memory devices are unable to store data for a period of adequate duration. As is well-know in the art, DRAM cells must be periodically refreshed to retain. Data retention errors often result from the inability of DRAMs memory cells to retain data between refreshes.
DRAM devices used in a computer system are normally tested during “boot-up” of the computer system. However, even if the DRAM devices pass the test during boot-up, they may malfunction during subsequent use. A DRAM device malfunction usually does not create too much of a problem because the system can simply be powered down and repaired by obtaining and installing a new DRAM device. Although the system must be shut down while the DRAM device is being installed, that also is usually not much of a problem. However, there are systems that cannot be shut down without creating somewhat greater problems. For example, shutting down a computer used to service a network of automatic teller (“ATM”) machines would render the ATM machines unusable for the entire period that the repair was being made. Another example results from malfunctions of a DRAM device used as system memory in a computer system performing a computation that may take a very long time, such as several weeks, to complete. If the DRAM device malfunctions well into the computation, it is often necessary to repeat the entire calculation after the malfunctioning DRAM device has been replaced. Unfortunately, there have been no suitable techniques to mitigate the adverse effects of such DRAM malfunctions.
There is therefore a need for a system and method that, for example, reduces the risk of unexpected memory device malfunctions from occurring during use of electronic systems, such as computer systems, containing DRAM devices.